import cv2
import numpy as np
camera=cv2.VideoCapture(0)
firstframe=None
while True:
	ret,frame = camera.read()
	if not ret:
		break
	gray=cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
	gray=cv2.GaussianBlur(gray,(21,21),0)
	if firstframe is None:
		firstframe=gray
		continue
	
	frameDelta = cv2.absdiff(firstframe,gray)
	thresh = cv2.threshold(frameDelta, 25, 255, cv2.THRESH_BINARY)[1]
	thresh = cv2.dilate(thresh, None, iterations=2)
	# cnts= cv2.findContours(thresh.copy(),cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
	
	x,y,w,h=cv2.boundingRect(thresh)
	frame=cv2.rectangle(frame,(x,y),(x+w,y+h),(0,0,255),2)
	cv2.imshow("frame", frame)
	cv2.imshow("Thresh", thresh)
	cv2.imshow("frame2", frameDelta)
	key = cv2.waitKey(1)&0xFF
	
	if key == ord("q"):
		break
 
camera.release()
cv2.destroyAllWindows()
